Amazon appears to be discouraging its sellers who use the Fulfillment by Amazon program from sending more dangerous items into its warehouses.

FBA is a program in which third-party sellers send their goods to be stored in Amazon warehouses before they are sold on Amazon.com. Items are then shipped out like a normal order by the e-commerce giant.

Amazon announced on its seller forum last Wednesday that it will be introducing a new fee for “dangerous” items like aerosol cans and lithium-ion batteries that sellers send to Amazon warehouses. The fees are higher than the regular fees Amazon charges for using Fulfillment by Amazon.

For example: a normal item with a shipping weight of between 10 and 16 ounces and is considered small would qualify for a fee of $US2.48, while a “dangerous” item the same size would carry a charge of $US3.45.

Amazon has a full list of items it considers “dangerous,” which mostly consists of items that are “flammable or pressurised aerosol substances and items that contain lithium-ion batteries.”

The new fees will go into effect on February 19, 2019, according to a note on Amazon’s forum for sellers. Amazon did not immediately respond to Business Insider’s request for further comment.

Amazon may have made it more expensive to sell and fulfil these risky items to discourage FBA sellers from sending them to warehouses. Earlier this month, a can of bear spray fell off a shelf in Amazon’s warehouse in Robbinsville, New Jersey. The can released fumes into the fulfillment center, injuring workers.